Known devices for compensation basically consist of a one large, central expansion joint and two mirror-symmetrical, smaller side expansion joints that are through the casing and connecting elements bind with the central. Bellows of sideways expansion joints have cylindrical housing diameter approximately equal to the diameter of the piping or ducting, while the diameter of the cylindrical casing of the central expansion joint bellow is greater than the diameter of piping or ducting on which the device is connected.
In contemporary practice, two kinds of solutions related to the installation of connecting elements are represented. In the first kind of solution connecting elements are placed inside the device in the area of fluid flow with diameter that is smaller than the inner diameter of piping. For other types of solutions, especially for devices with relatively small diameters, connecting elements are located outside the unit.
The solutions of In-line pressure balanced expansion joint for compensation of thermal dilatation with the binding elements located outside the unit are described in patent document U.S. Pat. No. 5,299,840, U.S. Pat. No. 5,248,170, BE544576 and FR1146661.
In the patent document CN2215063Y is described a solution for In-line pressure balanced expansion joint for compensation of thermal dilatation without connecting elements.
The Essence of the Invention
According to the invention the basic structure of the device for compensation of thermal dilatations of piping and ducting is equal to the known structure of the compensating devices, expansion joints. Device for compensation according to the invention basically consists of one large, central expansion joint and two mirror-symmetrical, smaller side expansion joints that are through the casings and connecting elements connected with the central.
The essence of the invention is contained in the design of the sideways expansion joints casings and the casing of the central expansion joint, place and manner of installation of connecting elements that connect the sideways expansion joints with the central expansion joint, and design of bracing the sides of the central expansion joint casing.
Each of the two sideway expansion joints consists of a bellows whose inner diameter is greater than the outer diameter of piping or ducting that connects the device for compensation. At the end of bellows welded pipe spools are welded and that are welded to the sides of the side expansion joint. Outer sides of sideway expansion joints have form of annular plate on which outer edges are welded spools of the bellows and on the inner edges of the pipe are welded spools to connect the device for compensation to the piping or ducting. The outer diameter of the external sides of sideway expansion joints is equal to the inner diameter of the bellows of sideway expansion joints and the inner diameter of the external sides of sideway expansion joint is equal to the outer diameter of the piping or ducting that connects the compensation device. The inner sides of sideway expansion joint consists of the sides of the central expansion joint on which are centrally welded inner pipe spools of side expansion joints.
Central expansion joint consists of a bellow whose inner diameter is greater than the inner diameter of sideway expansion joint bellows. At the ends of corrugated pipe of the central expansion joint pipe spools are welded and that are welded to the sides of the central expansion joint. Sides of the center expansion joint have form of annular plates whose outer edges are welded to pipe spools of central expansion joint bellow. The outer diameter of the sides of the central expansion joint is equal to the inner diameter of the bellow of central expansion joint and the inner diameter of the sides of the central expansion joint is equal to the outer diameter of the piping or ducting that connects the compensation device. On the inner surfaces of the central expansion joint sides reinforcements were made to the sides of the central expansion joint. Within an internal diameter of the sides of the central expansion joint reinforcements with reinforced ring that have cross section of hollow rectangle and are further reinforced with the rectangular radial fins within, were made. Outside the ring reinforcements, bellows rectangular radial fins triangular reinforcements in the form of radial ribs are made.
In the annular space which is defined with outer sides of the side expansion joints are bonding elements that interconnect casings of all three compensators. On a circle whose diameter is greater than the outer diameter of a piping or ducting and less than the inner diameter of side expansion joint bellows there are longitudinal connective elements at equal angular intervals which have the form of the full beam with circular cross section. Left side expansion joint is connected to a central expansion joint using tie rods so that their left ends are tightly welded to the left side of the left side expansion joint and their right ends are tightly welded to the right side of the central expansion joint. Right side expansion joint is connected to a central expansion joint using tie rods so that their right edges are tightly welded to the right sides of the right side expansion joint and their left ends are tightly welded to the left side of the central expansion joint. Penetrations in the surfaces and reinforcements through which tie rods breach have a diameter larger than the diameter of rods passing through them so that between tie beams and these components there is no contact at all. Tie rods on the left side of the expansion joint in relation to the tie rods on its right side are displaced for the half of angle that tie rods are spaced on each side of the device.
Properly placed retention and bracing prevent any deformation of individual cases in a series of expansion joints and the expansion joint system, ensuring proper stretching or shrinking of bellows in a series only due to thermal expansion and not due to excess pressure or vacuum that exists in the piping or ducting.
According to the invention design of expansion joint in which the tie rods are located in the annular space that is determined by the outer sides of the sideway expansion joints in relation to the solutions described in the technical condition has many advantages. Tie rods of this device does not obstruct fluid flow through the device as tie rods of device in which these elements are placed in the space through which the fluid flows. Tie rods of this device does not increase the dimensions of the device as tie rods of device in which these elements are located outside the device with larger diameter than the outer diameter of bellow of the central expansion joint. Therefore, according to the invention the solution enables the production of the expansion joint for piping and ducting of large diameters above 2 meters.